It’s long been known that breathing poor-quality air is linked to an increased risk of heart disease and stroke. Studies also have found that racial and ethnic minorities are more likely to live in areas near factories, freeways and other sources of environmental pollutants.

As the world’s population ages, there will be more and more dementia cases.

Dementia means the brain loses abilities, such as memory or communication skills. It’s caused in various ways, including strokes, narrowed or clogged arteries blocking blood flow, Alzheimer’s disease and head injuries.